Robotic low anterior resection for rectal cancer shows lower conversion and mortality vs laparoscopic approach

This is a systematic review and meta-analysis of studies comparing robotic low anterior resection (R-LAR) to laparoscopic low anterior resection (L-LAR) for rectal cancer. The population comprised patients undergoing low anterior resection for rectal cancer, with a total sample size of 82,149 patients across the included studies. The intervention was robotic low anterior resection, and the comparator was laparoscopic low anterior resection. Specific dosing or surgical protocol details were not reported in the input.

The primary outcome was not reported in the input. Key secondary outcomes included conversion rate, 30-day reoperation rate, 30-day mortality, complete total mesorectal excision, operative time, estimated blood loss, overall complications, major complications, anastomotic leakage, postoperative ileus, recovery parameters, length of hospital stay, readmission, circumferential margin positivity, lymph node yield, local recurrence, diverting ileostomy formation, disease-free survival, and overall survival.

For the main results, the conversion rate was significantly lower in R-LAR with an odds ratio (OR) of 0.45 (95% CI 0.40-0.51, p < 0.00001, I²=28%). The 30-day reoperation rate was significantly lower in R-LAR with an OR of 0.86 (95% CI 0.77-0.96, p = 0.01, I²=0%). The 30-day mortality was significantly lower in R-LAR with an OR of 0.65 (95% CI 0.52-0.82, p = 0.002, I²=0%). The rate of complete total mesorectal excision was higher in R-LAR with an OR of 2.71 (95% CI 1.38-5.33, p = 0.01, I²=72%). Operative time was significantly longer in R-LAR with a mean difference (MD) of +30.58 minutes (95% CI 13.71-47.45, p = 0.001, I²=97%).

For key secondary outcomes, estimated blood loss, overall complications, major complications, anastomotic leakage, postoperative ileus, recovery parameters, length of hospital stay, readmission, circumferential margin positivity, lymph node yield, local recurrence, diverting ileostomy formation, disease-free survival, and overall survival all showed no significant difference between R-LAR and L-LAR. No absolute numbers, effect sizes, or p-values were reported for these outcomes.

Safety and tolerability findings were not reported in the input. Adverse events, serious adverse events, discontinuations, and tolerability data were all listed as not reported.

These results compare to prior landmark studies in rectal cancer surgery, which have often included heterogeneous rectal procedures, limiting conclusions specific to low anterior resection. The current meta-analysis focuses specifically on low anterior resection, addressing a gap in prior literature. However, the input notes that most previous meta-analyses included heterogeneous rectal procedures, limiting conclusions specific to low anterior resection.

Key methodological limitations include the heterogeneity of included studies, as indicated by the high I² value of 97% for operative time, and the need for high-quality randomized trials to determine whether findings translate into meaningful clinical benefit. Potential biases were not explicitly reported, but the limitations suggest caution in interpreting results.

Clinical implications are that robotic LAR may reduce conversion, reoperation, and short-term mortality and may improve completeness of total mesorectal excision, although operative time is longer. Practice decisions should consider these potential technical advantages, but high-quality randomized trials are required to confirm clinical benefit.

Unanswered questions remain regarding the long-term oncologic outcomes, cost-effectiveness, and whether the observed advantages translate into improved survival or quality of life. The certainty of evidence was evaluated using the GRADE approach, but specific certainty levels were not reported.